The present invention relates generally to computer systems, and more particularly to inserting text objects in a pen-based computer system.
Computerized personal organizers are becoming increasingly popular with a large segment of the population. Computerized personal organizers tend to be small, lightweight, and relatively inexpensive, and can perform such functions as keeping a calendar, an address book, a to-do list, etc. While many of these functions can also be provided in conventional computer systems, personal organizers are very well suited to the personal organization task due to their small size and portability. Personal organizers are available from such companies as Sharp and Casio of Japan.
A relatively new form of computer, the pen-based computer system, holds forth the promise of a union between the power of a general purpose computer and the functionality and small size of a personal organizer. A pen-based computer system is typically a small, hand-held computer where the primary method for inputting data includes a "pen" or stylus. A pen-based computer system is commonly housed in a generally rectangular enclosure, and has a dual-function display assembly providing a viewing screen along one of the planar sides of the enclosure. The dual-function display assembly serves as both an input device and an output device. When operating as an input device, the display assembly senses the position of the tip of a stylus on the viewing screen and provides this positional information to the computer's central processing unit (CPU). Some display assemblies can also sense the pressure of the stylus on the screen to provide further information to the CPU. When operating as an output device, the display assembly presents computer-generated images on the screen.
The dual-function display assemblies of pen-based computer systems permit users to operate the computer as a computerized notepad. For example, graphical images can be input into the pen-based computer by merely moving the stylus on the surface of the screen. As the CPU senses the position and movement of the stylus, it generates a corresponding image on the screen to create the illusion that the stylus is drawing the image directly upon the screen, i.e., that the stylus is "inking" an image on the screen. With suitable recognition software, text and numeric information can also be entered into the pen-based computer system in a similar fashion.
Pen-based systems are limited in their ability to perform word processing as efficiently as keyboard-based systems. Unlike keyboard-based systems in which typing in data is simple and convenient, pen-based systems are restricted to inputting text by using the stylus, which although simple, is not as convenient as typing for accurate, extended textual entry into the computer system. However, some of the basic word processing functions can be achieved on a pen-based system to aid in making text entry into a pen-based system more convenient. One such technique is the insertion of new text into already existing text. In keyboard-based systems, insertions are performed by locating an insertion point and then continuing with the typing of the new text. No existing text is overwritten by the new text, and all the characteristics, such as margin, font, justification, etc., that are established for that portion of the document within the processing program are maintained for the newly entered data. What is needed is a method for achieving such insertions on a pen-based system.